The invention relates to a base and cover arrangement for an electric machine with a cover covering the stator. The stator includes a lamination stack carrying the winding and held together by shield-like pressure plates projecting beyond the lamination stack and tightening devices. The arrangement can be configured in accordance with the desired type of protection. In addition, the stator of this machine is mounted on a base structure which also supports the bearings. Such an electric machine is described in the Deutsche Auslegeschrift 1,121,199. The base of this known machine consists of a plate and four corner post and it supports fastening means for supporting the stator which is configured as a separate component. Also mounted on the base are lateral covers extending to the machine center, the bearings, and a cap located above the machine center. The lateral covers and the cap can be removed without thereby impairing the alignment of the stator. Therefore, the stator is readily accessible from all sides for inspection and servicing.
Because of the fact that the covers and cap of the known machine are physically separated from the stator, the cap in particular can be modified to suit the type of protection required. This allows an easy adaptation to the desired cooling system possible. However, no steps are taken to avoid transmission of structure-borne sound so that the covers as well as the cap, which are interconnected by the base, are sound-emitting surfaces. The known machine merely has provisions for the arrangement of noise suppressors inside the cover in front of the air intake and/or outlet openings.
It is an object of the invention to provide a base and cover arrangement for an electric machine with which its stator is readily accessible for servicing but at the same time, the machine will operate with a very low noise level.